The invention relates to a turbopump comprising a turbine fed with hot gas, a pump driven by the turbine and fed with liquid fluid, and a hot gas exhaust pipe situated downstream from the turbine.
Such turbopumps are known, e.g. for feeding propellant to the combustion chamber of a rocket engine.
By way of example, Document EP 1 672 270 in the name of the Applicant describes a turbopump in accordance with the precharacterizing portion of claim 1.
The turbine drives the pump (or more precisely the rotor portion of the pump) at speeds that can be very high and can reach several thousands of revolutions per minute. Consequently, the component elements of the turbopump are subjected to high levels of stress and of vibration. In certain circumstances, the frequencies of such vibration can correspond to resonant modes of certain elements of the turbopump, and in particular of certain parts of the turbine, which can lead to the parts concerned being damaged. Such vibration has a negative impact on the operation of the turbopump and on its lifetime.
In particular, it has been observed that high levels of vibration affect the upstream parts of the turbine (first disk of the turbine that is close to the pump). If this vibration is not damped sufficiently, the vibratory phenomenon can become large, thereby leading to significant damage to the first disk of the turbine, or indeed to destruction of the turbine.